Do you recognize this mystery plant?

In this column, we have had several members of the philodendron family, the Araceae, as subject of wonder. The philodendron family is a large one, with several thousand species. These species are conveniently referred to as “aroids.”

You might remember the time we had “Golden club”, Orontium aquaticum, which is a native member of various wetlands here in the Southeast. Up in New England, there is the famous “skunk cabbage” as a member, Symplocarpus foetidus, which comes up before the snow melts. And of course, surely everyone knows and loves our dainty “Jack in the pulpit” (Arisaema triphyllum), which is common in the eastern half of the U.S.

Most members of the family are decidedly tropical, however, and it is among these that we have some of our most favorite cultivated plants: Climbing philodendrons and “Mother in Law” plant (Dieffenbachia) are well known indoors, just as colorful Caladiums and Elephant-ear (species of Colocasia and Alocasia) are popular and easy to grow outdoors (they need a lot of water and a lot of sun).

Additionally, important food sources are supplied by the starchy tubers of taro (Colocasia esculenta) and malanga (Xanthosoma sagittifolia), which are commonly eaten in tropical regions around the world.

Aroid species have a number of things in common, the most prominent being characters of the flowering structures. Typically, when an aroid blooms, it produces a stalk-like spike with plenty of tiny flowers on the surface. This is called the “spadix.”

The spadix is practically always surrounded by a green or otherwise colorful bract, called a “spathe”. “Golden club” is an aroid whose spadix is not surrounded by a spathe.

This week’s mystery plant is a perfectly good aroid. It was blooming in a yard here in Columbia last week, and caused quite a stir! Each year it produces a single, colossal, palm-like leaf, about 5 feet tall. It only blooms once every several years.

The “flower” is actually a massive and somewhat provocative inflorescence. A purplish-green stalk, about 3 inches in diameter, holds up a thick spadix that is surrounded by a shockingly veiny, purplish-red, fleshy spathe. Above the flowers, the spadix terminates in a prominently lurid, tapering sterile appendage.

True to its genus, this plant produced a strong stink, largely suggestive of a pile of ripe, dead rats. This makes sense, as flies and other carrion-loving insects delight in visiting (and thereby pollinating) the flowers. The inflorescence lasts only a few days, soon collapsing and rotting, and then the plant will send up its single leaf.

This species is native to warm forests of Vietnam and southern China, and is otherwise widely grown as a curiosity. It is fairly easy to grow either in a greenhouse or outside, but if it blooms for you, be prepared for some raised eyebrows (and held noses).

John Nelson is the curator of the A. C. Moore Herbarium at the University of South Carolina, in the Department of Biological Sciences. As a public service, the herbarium offers free plant identifications. For more information, visit www.herbarium.org, call 803-777-8196 or email nelson@sc.edu.